Forget the phrasebook, or even Rosetta Stone software; the next time you’re travelling in a foreign land, you’ll likely just reach for your smartphone when you need to communicate in the local language, and have an app do all the heavy lifting. It’s long been a dream of science fiction (Babelfish inserted into the ear provided the service in Douglas Adams’ celebrated Hitchhiker’s Guide to the Galaxy series), but now technological developments are coalescing in a way that makes on-demand translation more practically possible than ever before, and startups are taking advantage.

Big companies (like Google via Google Translate) were among the first to play with online translation, but the field is widening thanks to young companies that see opportunities to do more and appeal to very specific use cases. There’s Word Lens, for instance, the app that made waves when it unveiled its software last year that uses optical character recognition tech to translate signage snapped with a smartphone’s camera. And SayHi Translate has recently rocketed to the tops of the iOS App Store charts on the strength of a recent update that introduces support for a lot of new languages, and improvements to its spoken word translation.

SayHi CEO and founder Lee Bossio told BetaKit in an interview that spoken word was an obvious target for his company, and one he identified based on personal experience.

“I spent a lot of time with a family member in a hospital while she had major surgery, and ended up following around interpreters,” he said. “I found it fascinating to see what they did, but realized they were still completely overwhelmed. I chose spoken word because it seemed so obvious, but just wasn’t done well.”

Bossio said the response has been tremendous since the app’s launch in June of last year, and has ramped up recently. “It’s doing huge numbers,” he said. “Our AWS architecture is spawning EC2 instance after EC2 instance after EC2 instance. It’s exploded on a scale much larger than we expected, but thankfully our intense over-engineering of everything has prepared us for it.”

While originally intended mostly for use by medical professionals and travellers, SayHi is now being used by a much larger base than Bossio originally envisioned, and the company is also looking into possible revenue opportunities to be had in offering businesses custom translation services.

Santiago, Chile-based startup Babelverse is also seeing a lot of opportunity is supporting businesses with specific online translation tools. It launched its product last week at The Next Web Conference 2012, where it also provided online translation services for live videocast footage from the startup event. Babelverse uses human-powered translation, sourced from freelance interpreters working remotely around the world. Babelverse is keen to differentiate its service from others in the space.

“What we are dealing with is Interpreters, since we are focused on the interpretation of spoken word in real-time,” he said, and he maintainthat the distinction is key. “Translators work only with text, this is an important point to clear up, we are bring interpretation to the masses.”

Semantics aside, Babelverse is starting with online event interpretation, which should provide them plenty of opportunities given how many conferences are simultaneously webcast for people who can’t be there in person. Webinars and online webcast business events are expected to grow to be a $400 million business by 2014, according to a recent report. But Babelverse’s value extends well beyond that specific use case; human powered on-demand translation via connected devices could apply to almost any situation where an in-person translator was once required.

Google has been dealing in mobile online translation for a while now, but they aren’t the only big player who would obviously benefit from online translation. Apple’s Siri personal assistant is designed to provide all kinds of services designed to help travellers and people looking to interact with their surroundings; adding translation services to the voice-powered Siri is a logical next step. In other words, it’s an area where there could be a lot of M&A activity in the near future.

Interestingly, both machine-powered and human-sourced translation services are made better thanks to new mobile tech, like real-time always-on connectivity for web workers, and new, smarter algorithms that make natural language interpretation easier for computing devices. People looking around for supplemental income in a tough global economic climate can be leveraged to do quick or crowdsourced translation tasks, and faster mobile networks and more powerful remote servers make computer-based translation faster and more efficient.

Even with larger players taking a keen interest in online translation, Bossio told BetaKit that he thinks the real trend-setters in this space will be smaller companies. “We can adapt very quickly since we’re small, and take advantage of emerging technologies that are just too risky for larger companies to take,” he pointed out. We’ll have to see whether that ability to adapt quickly to a market seeing a lot of change on the tech side will help SayHi, Babelverse, Wordlens and other small companies exploring translation opportunities stay ahead of the curve.